Mr. Sokolich is holding a fundraiser Monday for a Democrat looking to unseat the Republican executive overseeing Bergen County, the area where the bridge closures took place last September.

A Democrat who rarely gets involved in party politics, Mr. Sokolich is supporting Democrat Jim Tedesco. The former mayor of Paramus, N.J., is running against Kathleen Donovan, a Republican seeking a second four-year term.

Mr. Sokolich, the mayor of Fort Lee, N.J., at the foot of the bridge, said he was holding a rare fundraiser because of his 15-year friendship with Mr. Tedesco and to support a fellow mayor.

“It’s something I rarely do. It’s something I’m usually low-key with, including endorsements, as you know,” Mr. Sokolich said Friday.

Mr. Sokolich said the fundraiser for Mr. Tedesco had nothing to do with the bridge. He had no comment on Ms. Donovan’s leadership or response to the incident and declined to comment on a criminal investigation led by New Jersey prosecutors as to whether federal laws were broken.

Bergen County Democrats have seized on the bridge as an issue in the race and have attacked Ms. Donovan for not doing more to respond to the lane closures when they occurred.

“It’s a shame Kathe Donovan waited 127 days to even comment on the lane closures and never offered Fort Lee officials any support,” said Michael Pagan, Mr. Tedesco’s campaign manager.

Mark Campbell, Ms. Donovan’s campaign manager, dismissed the attacks as an attempt by Democrats to gain attention, and said that the county executive responded to the lane closures appropriately and condemned them.

“Kathe Donovan had nothing to do with the lane closures and acted responsibly every step of the way,” Mr. Campbell said.

The evening fundraiser at Mr. Sokolich’s home costs $250 and more than 100 people have indicated they will attend, he said. The election will be held on Nov. 4.